CN209840083U - Multistage air distribution radial outer thick inner thin cyclone burner - Google Patents
Multistage air distribution radial outer thick inner thin cyclone burner Download PDFInfo
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- CN209840083U CN209840083U CN201920510791.0U CN201920510791U CN209840083U CN 209840083 U CN209840083 U CN 209840083U CN 201920510791 U CN201920510791 U CN 201920510791U CN 209840083 U CN209840083 U CN 209840083U
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- secondary air
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- flaring
- air
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- 239000003245 coal Substances 0.000 claims abstract description 118
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 abstract description 52
- 230000000694 effects Effects 0.000 abstract description 6
- 238000010304 firing Methods 0.000 abstract 1
- 239000000843 powder Substances 0.000 description 50
- 238000002485 combustion reaction Methods 0.000 description 43
- 239000000203 mixture Substances 0.000 description 14
- 238000002156 mixing Methods 0.000 description 11
- 238000010992 reflux Methods 0.000 description 11
- 230000003111 delayed effect Effects 0.000 description 7
- 230000002035 prolonged effect Effects 0.000 description 7
- 239000002817 coal dust Substances 0.000 description 6
- 239000000446 fuel Substances 0.000 description 5
- 230000014759 maintenance of location Effects 0.000 description 5
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 4
- 239000003546 flue gas Substances 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 239000002802 bituminous coal Substances 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 230000002093 peripheral effect Effects 0.000 description 3
- 239000002585 base Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000004939 coking Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000009991 scouring Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 125000006850 spacer group Chemical group 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- RHZUVFJBSILHOK-UHFFFAOYSA-N anthracen-1-ylmethanolate Chemical compound C1=CC=C2C=C3C(C[O-])=CC=CC3=CC2=C1 RHZUVFJBSILHOK-UHFFFAOYSA-N 0.000 description 1
- 239000003830 anthracite Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000012458 free base Substances 0.000 description 1
- 239000003077 lignite Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000003476 subbituminous coal Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Abstract
The utility model provides a radial outer thick interior thin cyclone burner of multistage air distribution, it relates to a combustor, the utility model discloses in order to solve current combustor because the concentrated rate of buggy concentrator is low, be unfavorable for NOx's reduction and the stability of burning, the poor stability in combustor backward flow district can not adapt to the problem of the burning of many varieties coal well. The utility model comprises a central tube, a primary air pipe, an inner secondary air pipe, a middle secondary air pipe, an outer secondary air pipe, a pulverized coal concentrator and a spoiler; the central pipe, the primary air pipe, the inner secondary air pipe, the middle secondary air pipe and the outer secondary air pipe are sequentially sleeved together from inside to outside, and the outlet ends of the central pipe, the primary air pipe, the inner secondary air pipe, the middle secondary air pipe and the outer secondary air pipe are sequentially provided with a primary air flaring opening, an inner secondary air flaring opening, a middle secondary air flaring opening and an outer secondary air flaring opening; a pulverized coal concentrator and a flow equalizing ring are arranged in the primary air duct. The utility model discloses make nitrogen oxide reduce, the firing capacity of combustor obtains improving, has improved the steady effect of burning of combustor. The utility model is suitable for a boiler.
Description
Technical Field
The invention relates to a combustor, in particular to a multi-stage air distribution radial outer thick inner thin cyclone combustor.
Background
The traditional boiler cyclone pulverized coal burner is easy to form an oxygen-enriched combustion area due to strong disturbance of air flow at the initial stage of combustion and quick mixing of secondary air, and has short flame, concentrated heat release and high flame temperature, so that the NOx emission is very high. Therefore, a plurality of low NOx cyclone burners appear, which divide secondary air into a plurality of stages, send pulverized coal into a hearth through primary air, prolong the combustion time of the pulverized coal through the staged combustion of the plurality of stages of air, and send only pulverized coal into a primary combustion zone for the purpose of delaying mixing and controlling the combustion process through air stagingMaintaining the air quantity required by stable ignition and volatile matter combustion to form dense phase core flame and reduce the temperature peak value of the flame; because the mixing of secondary air is delayed and a reduction zone is formed, not only the generation amount of NOx can be reduced, but also part of NO can be enabledxAnd (4) reducing.
The existing low-NOx outer-thick inner-thin cyclone burner adopts a Venturi coal dust concentrator as a coal dust concentrator, primary air coal dust is radially distributed in an outer-thick inner-thin manner after being concentrated by the concentrator, namely, the coal dust concentration in the inner wall area of a primary air pipe is high, the coal dust concentration in the outer wall area of a central air pipe is low, the staged combustion of fuel is realized, the generation of nitrogen oxides can be effectively reduced, and the ignition stability of the coal dust is improved, the concentration rate of the concentrator is low and generally ranges from 60% to 75%, the reduction and combustion stability of NOx are not facilitated, and the stability of a backflow area of the burner is poor, so that the burner can only adapt to bituminous coal and lignite with high volatile matter, and the incomplete combustion phenomenon can occur to other coal types.
Disclosure of Invention
The invention provides a multi-stage air distribution cyclone burner with radially thick outer parts and light inner parts, which aims to solve the problems that the existing cyclone burner is not beneficial to the reduction of NOx and the combustion stability due to low concentration rate of a pulverized coal concentrator, and the burner is poor in stability of a backflow area, can only adapt to coal types with high volatile matters and cannot be well adapted to the combustion of various coals.
The technical scheme adopted by the invention for solving the technical problems is as follows:
the first scheme is as follows: a multi-stage air distribution cyclone burner with radially thick outer part and thin inner part comprises a central tube, a primary air tube, an inner secondary air tube, a middle secondary air tube, an outer secondary air tube, an inner cyclone, an outer cyclone, a secondary air bellow, a spoiler, a pulverized coal concentrator and a flow equalizing ring;
the central tube, the primary air tube, the inner secondary air tube, the middle secondary air tube and the outer secondary air tube are sequentially sleeved together from inside to outside, a primary air channel, an inner secondary air channel, a middle secondary air channel and an outer secondary air channel are sequentially formed between the adjacent primary air tube and the adjacent inner secondary air tube from inside to outside, the outlet ends of the primary air tube, the inner secondary air tube, the middle secondary air tube and the outer secondary air tube are correspondingly provided with a primary air flaring, an inner secondary air flaring, a middle secondary air flaring and an outer secondary air flaring one by one, the spoiler is arranged on the inner wall of the outlet end of the primary air tube, the inner swirler is arranged in the middle secondary air channel, and the outer swirler is arranged in the outer;
the pulverized coal concentrator comprises a supporting plate and N concentrating rings, wherein N is an integer of 2-5;
the diameters of the N concentration rings are sequentially increased along the flowing direction of the primary air pulverized coal, a certain distance is reserved between every two adjacent concentration rings, the N concentration rings are fixedly connected together through a support plate, the support plate is fixedly connected to the outer wall of the central pipe, and the N concentration rings are arranged on one side, close to the outlet of the central pipe, of the central pipe;
the flow-equalizing ring is arranged on the inner wall of the primary air pipe, and the flow-equalizing ring is arranged adjacent to one side of the concentration ring with larger diameter.
Furthermore, the spoiler is composed of M trapezoidal plates with plate surfaces on the same plane, wherein M is an integer of 8-16, the M trapezoidal plates are uniformly arranged at the outlet end of the inner wall of the primary air pipe, two adjacent trapezoidal plates are arranged at a certain gap, and the length of each trapezoidal plate is 0.1-0.4 times of the distance from the outer wall of the central pipe to the inner wall of the primary air pipe.
Scheme II: a multi-stage air distribution radial outer thick inner thin cyclone burner comprises a central tube, a primary air tube, an inner secondary air tube, an outer secondary air tube, an inner cyclone, an outer cyclone, a secondary air box, a spoiler, a pulverized coal concentrator, a flow equalizing ring and a spacing tube;
the vortex generator is arranged on the inner wall of the outlet end of the primary air pipe, the inner vortex generator is arranged in the inner secondary air passage, and the outer vortex generator is arranged in the outer secondary air passage;
the pulverized coal concentrator comprises a supporting plate and N concentrating rings, wherein N is an integer of 2-5;
the diameters of the N concentration rings are sequentially increased along the flowing direction of the primary air pulverized coal, a certain distance is formed between every two adjacent concentration rings, the N concentration rings are fixedly connected together through a support plate, the support plate is fixedly connected to the outer wall of the central pipe, and the N concentration rings are arranged on one side, close to the outlet of the central pipe, of the central pipe;
the flow-equalizing ring is arranged on the inner wall of the primary air pipe, and the flow-equalizing ring is arranged adjacent to one side of the concentration ring with larger diameter.
Compared with the prior art, the invention has the following beneficial effects:
firstly, the burner system of the invention has low resistance, the total secondary air resistance is not more than 800Pa, the power consumption of the fan is saved, the burner system can well keep the stability of combustion under all loads, and the nozzle does not generate coking.
Compared with the prior art, the invention realizes the concentration separation of primary air pulverized coal through a novel pulverized coal concentrator and a flow-equalizing ring, the separation efficiency can reach 90 percent, the fuel staged combustion of the primary air pulverized coal is realized, the primary air speed near the wall of the primary air pipe can be well reduced, the scouring of the primary air pulverized coal mixture to the wall of the primary air pipe is effectively reduced, and the service life of equipment is prolonged. The primary air carrying coal powder enters the primary air channel, under the concentration action of the coal powder concentration device, the primary air coal powder is divided into a thick part and a thin part, a thick coal powder area is formed near the inner pipe wall area of the primary air, a thin coal powder area is formed near the outer surface area of the central air pipe, the concentration ratio of the coal powder is 75-90%, the distribution form that the primary air coal powder is thick outwards and thin inwards along the primary air pipe is realized, a large amount of coal powder is concentrated near the inner surface of the primary air pipe and sprayed into a hearth, the staged combustion of the coal powder is realized, the coal powder amount of the middle high-temperature backflow area is increased, the reducing atmosphere of the central backflow area is strengthened, the retention time of the coal powder in the backflow area is prolonged.
Thirdly, the invention divides the air of main combustion into three layers of inner secondary air, middle secondary air and outer secondary air to increase the air classification degree, and at the same time, a stable central reflux area is formed at the outlet of the burner, a low-speed area exists between the primary air and the secondary air to delay the mixing of the primary air and the secondary air, because the inner secondary air is a straight secondary air with small air quantity and low air speed, the penetration capability and the primary air entrainment capability are weak, the primary air can not be entrained early, the distance between the primary air and the peripheral main secondary air is increased, the mixing of the primary air and the swirling secondary air is delayed, the reducing atmosphere of the central reflux area is enhanced, the generation of nitrogen oxides is inhibited, meanwhile, the middle secondary air and the outer secondary air form swirling air to be jetted into a hearth after passing through the inner swirler and the outer swirler, the speed is higher, and the effect is to finish the carbon-exhaustion combustion at the area far away from the outlet of the burner, and ensures that the near-combustion zone forms a stable reflux zone.
The invention divides the air of the main combustion into inner secondary air and outer secondary air for staged combustion, and a spacing cylinder is arranged between the primary air pipe and the inner secondary air pipe, a stable central reflux area is formed at the outlet of the invention, and a low-custom area is arranged between the primary air and the secondary air, so that the mixing of the primary air and the secondary air is delayed. Meanwhile, the inner secondary air and the outer secondary air form swirling air after passing through the inner swirler and the outer swirler and are injected into the hearth, the speed is high, the effect is to finish the combustion of unburned carbon at an outlet area far away from the hearth, and a stable backflow area is formed in a near area.
The inner surface of the outlet end of the primary air pipe is provided with a spoiler, the spoiler consists of M trapezoidal plates and is uniformly arranged on the circumference of the primary air pipe, and M is an integer of 8-16; the length of the turbulator is 0.1-0.4 times of the distance between the central air pipe and the primary air pipe, under the combined action of the turbulator, primary air thick pulverized coal is distributed in a thick pulverized coal and a thin pulverized coal alternate in the circumferential direction under the action of the turbulator, so that the local pulverized coal concentration of the primary air outlet section is improved, the staged combustion of the pulverized coal is enhanced, and the burner stable combustion performance is particularly improved, and the generation of nitrogen oxides is reduced. Meanwhile, due to the existence of the vortex generator, when the pulverized coal airflow flows around the vortex generator, a small vortex ring is formed on the circumference of the pulverized coal airflow and attached to the root of the high-temperature backflow area, and in the small vortex area, the pulverized coal is easy to catch fire to strengthen the ignition characteristic of the pulverized coal, so that the stable combustion characteristic of the combustor is ensured.
And sixthly, flaring is arranged on the middle secondary air and the outer secondary air, so that the swirl strength of the inner swirl and the outer swirl secondary air is enhanced, the mixing of the middle secondary air, the outer secondary air and primary air powder is delayed, the retention time of the coal powder in a central reflux area of a reducing atmosphere is prolonged, an anoxic environment is formed in a near burner area, the reduction of NOx is facilitated, and the generation of nitrogen oxides is reduced.
Seventhly, under the combined action of the specific pulverized coal concentration device, the flaring structure and the specific air distribution, a stable central backflow area is formed in a primary air powder jet area at the outlet of the combustor, primary air with thick outside and light inside can be sucked into the backflow area by the central backflow area, high-temperature flue gas is brought back to a burner area to heat primary air powder, ignition of pulverized coal is promoted, stability of flame is guaranteed, stable combustion of different loads is achieved, the oxygen content of the returned high-temperature flue gas is low, the backflow area is in an anoxic environment, and generation of nitrogen oxides is inhibited.
The concentration rate of the coal powder concentration device is more than 90%, the reduction and combustion stability of NOx is further improved, the special coal powder concentration device can better adapt to the combustion of different kinds of coal by adopting a specific flaring combined structure, and the combustion stability is better.
Drawings
FIG. 1 is an overall structure diagram of a first embodiment of the present invention;
FIG. 2 is an enlarged view of a portion of FIG. 1 at the point I, wherein the direction of the arrow is the direction of the pulverized coal transportation;
fig. 3 is a schematic view of a spoiler 7;
FIG. 4 is an enlarged view of a portion of FIG. 1 at II;
FIG. 5 is a partial schematic view of a first version of the exit port of FIG. 1;
FIG. 6 is a partial schematic view of a second version of the outlet of FIG. 1;
FIG. 7 is an overall structure diagram of a second embodiment of the present invention;
FIG. 8 is a partial schematic view of a first version of the outlet of FIG. 7;
FIG. 9 is a partial schematic view of a second version of the outlet of FIG. 7;
in fig. 1 and 7, arrows in the primary air pipe 2 are the coal powder conveying direction, and arrows at the inner secondary air pipe 3, the middle secondary air pipe 4 and the outer secondary air pipe 5 are the air inlet direction.
Detailed Description
The first embodiment is as follows: the embodiment is described with reference to fig. 1 to 4, and the multi-stage air distribution radial outer rich-lean cyclone burner of the embodiment comprises a central pipe 1, a primary air pipe 2, an inner secondary air pipe 3, a middle secondary air pipe 4, an outer secondary air pipe 5, an inner cyclone 13, an outer cyclone 14, a secondary air bellow 15, a spoiler 7, a pulverized coal concentrator 6 and a flow equalizing ring 8;
the central tube 1, the primary air tube 2, the inner secondary air tube 3, the middle secondary air tube 4 and the outer secondary air tube 5 are sequentially sleeved together from inside to outside, and a primary air channel, an inner secondary air channel, a middle secondary air channel and an outer secondary air channel are sequentially formed between the adjacent two from inside to outside, the outlet ends of the primary air tube 2, the inner secondary air tube 3, the middle secondary air tube 4 and the outer secondary air tube 5 are correspondingly provided with a primary air flaring 9, an inner secondary air flaring 10, a middle secondary air flaring 11 and an outer secondary air flaring 12 one by one, the spoiler 7 is arranged on the inner wall of the outlet end of the primary air tube 2, the inner swirler 13 is arranged in the middle secondary air channel, and the outer swirler 14 is arranged in the outer secondary air channel;
the pulverized coal concentrator 6 comprises a support plate 6-1 and N concentrating rings 6-2, wherein N is an integer of 2-5;
the diameters of the N concentration rings 6-2 are sequentially increased along the flowing direction of the primary air pulverized coal, the adjacent two concentration rings 6-2 are arranged at a certain distance, the N concentration rings 6-2 are fixedly connected together through a support plate 6-1, the support plate 6-1 is fixedly connected to the outer wall of the central tube 1, and the N concentration rings 6-2 are arranged at one side adjacent to the outlet of the central tube 1;
the flow equalizing ring 8 is arranged on the inner wall of the primary air pipe 2, and the flow equalizing ring 8 is arranged adjacent to one side of the concentration ring 6-2 with larger diameter.
Preferably, the outer cyclone 14 is installed in the secondary air bellow 15, and the horizontal section of the primary air duct 2 and the horizontal section of the outer secondary air duct 5 are respectively welded on the secondary air bellow 15.
The pulverized coal concentrator 6 comprises a support plate 6-1 and N concentrating rings 6-2, wherein N is an integer of 2-5;
the diameters of the N concentration rings 6-2 are sequentially increased along the flowing direction of the primary air pulverized coal, a certain distance is formed between every two adjacent concentration rings 6-2, the N concentration rings 6-2 are fixedly connected together through a support plate 6-1, the support plate 6-1 is fixedly connected to the outer wall of the central tube 1, and the N concentration rings 6-2 are arranged on one side, close to the outlet of the central tube 1.
Preferably, the concentrating ring 6-2 is of a stainless steel outer wear-resistant ceramic structure, so that the wear resistance of the concentrating ring is improved, and the service life of the concentrating ring is prolonged.
The inlets of the inner secondary air pipe 3, the middle secondary air pipe 4 and the outer secondary air pipe 5 are respectively provided with an air damper, and the size and the strength of the central backflow area are adjusted by adjusting the size of each air damper, so that the requirements of different coal types, air quantity and loads are met, and the coal type adaptability of the combustor is improved.
In the embodiment, the primary air-powder mixture is gradually concentrated under the action of the coal powder concentrator 6, the coal powder airflow is divided into a thick coal powder region and a thin coal powder region which are formed near the inner wall region of the primary air pipe and a thin coal powder region which is formed near the outer surface region of the central air pipe, and the coal powder concentration distribution is radially thick and thin inside, so that the staged combustion of the coal powder is realized, the coal powder amount of the middle high-temperature backflow region is increased, the ignition heat of the coal powder is reduced, the retention time of the coal powder in the backflow region is prolonged, the reducing atmosphere of the central backflow region is enhanced, and the generation of nitrogen oxides.
The secondary air is divided into inner secondary air, middle secondary air and outer secondary air, the air classification degree in the radial direction of the invention is increased, the inner secondary air is one stream of direct current air, the air volume is smaller, and an inner secondary air flaring is added at the same time.
The outlet area of the invention forms a stable central reflux area, the reflux area is stable, the reflux effect is good, primary air with thick outside and light inside can be sucked into the reflux area, high-temperature flue gas at the outer side is sucked back to the vicinity of the outlet of the combustor, primary air pulverized coal is heated, pulverized coal ignition is promoted, flame stability is kept, and meanwhile, the central reflux area at the outlet area of the primary air is in an anoxic state due to the low oxygen content of the sucked high-temperature flue gas, a reducing atmosphere is formed, and the generation of nitrogen oxides is reduced.
The second embodiment is as follows: referring to fig. 2, the present embodiment is described, in which N concentrating rings 6-2 are all conical rings, the tapers of the N concentrating rings 6-2 are all equal, and an included angle δ between a generatrix of each concentrating ring 6-2 and a center line of a central tube 1 is 20 ° to 40 °.
Other components and connections are the same as in the first embodiment.
The third concrete implementation mode: the present embodiment is described with reference to fig. 1, 5, and 6, in which the flow-equalizing ring 8 of the present embodiment is disposed on the inner wall of the primary air duct 2 between the primary air flaring 9 and the pulverized coal concentrator 6, the distance Ls from the end of the flow-equalizing ring 8 adjacent to the primary air flaring 9 to the end of the primary air flaring 9 is 4 to 8 times the distance S1 from the outer wall of the central tube 1 to the inner wall of the primary air duct 2, and the thickness Hs of the flow-equalizing ring 8 is 0.04 to 0.1 times the distance S1 from the outer wall of the central tube 1 to the inner wall of the primary air duct 2.
Other components and connection modes are the same as those of the second embodiment.
The fourth concrete implementation mode: the present embodiment is described with reference to fig. 3, in the present embodiment, the spoiler 7 is composed of M trapezoidal plates, the plate surfaces of the M trapezoidal plates are on the same plane, M is an integer of 8 to 16, the M trapezoidal plates are uniformly arranged at the outlet end of the inner wall of the primary air duct 2, two adjacent trapezoidal plates are arranged with a certain gap, and the height S of each trapezoidal plate is 0.1 to 0.4 times the distance S1 between the outer wall of the central tube 1 and the inner wall of the primary air duct 2.
The utility model discloses add spoiler 7, the dense buggy of a wind is the distribution mode of the alternate thick buggy one light buggy of dense and light one on the circumferencial direction under spoiler 7's effect, has improved the local buggy concentration of a wind outlet section and has strengthened the fractional combustion of buggy, is favorable to improving the combustor surely to burn the performance and reduce nitrogen oxide's formation very much. Meanwhile, due to the existence of the spoiler 7, when the pulverized coal airflow flows around the spoiler 7, a small vortex ring is formed on the circumference of the pulverized coal airflow and attached to the root of the high-temperature backflow area, and in the small vortex area, the pulverized coal is easy to catch fire to strengthen the ignition characteristic of the pulverized coal, so that the stable combustion characteristic of the combustor is ensured.
Other compositions and connection relations are the same as those of the third embodiment.
The fifth concrete implementation mode: referring to fig. 5, the present embodiment will be described, in which the range of the expansion angle β of the primary air flare 9 is 15 to 25 °, the range of the expansion angle γ of the middle secondary air flare 11 is 20 to 25 °, the range of the expansion angle θ of the outer secondary air flare 12 is 20 to 25 °, and the range of the expansion angle θ of the inner secondary air flare 10 is 20 to 25 °.
The flaring combination with different angles can form a stable backflow area at the outlet area of the combustor, and the invention can select different flaring angle combinations according to different coal types and different hearth forms so as to achieve the best combustion effect, reduce the generation of nitrogen oxides and reduce the high-temperature corrosion of the water cooling wall. If each flaring angle is too large, the airflow expansion angle is increased, an open backflow area is formed, combustion is unstable and coking of a water wall is caused, if the flaring angle is too small, primary air and secondary air are mixed too early, and the range of the backflow area is too small, so that stable combustion of pulverized coal is not facilitated.
In the embodiment, the secondary air flaring 11 and the primary air flaring 9 delay the mixing of primary air powder and secondary air, prolong the retention time of the coal powder in a reducing atmosphere and reduce the generation of nitrogen oxides.
Other compositions and connection relations are the same as those of the fourth embodiment.
The sixth specific implementation mode: in the present embodiment, the end portions of the inner overfire air flares 10, the intermediate overfire air flares 11 and the end portions of the primary air flares 9 are flush with each other, as described above with reference to fig. 5.
Other components and connection relationships are the same as those in the fifth embodiment.
The seventh embodiment: the present embodiment is described with reference to fig. 5, and the length L4 of the primary air flare 9, the length L3 of the inner secondary air flare 10, and the length L2 of the middle secondary air flare 11 in the present embodiment are equal; the length L4 of the primary air flaring 9 is 0.4-0.7 times of the length L1 of the outer secondary air flaring 12.
The primary air-powder mixture from the primary air nozzle is premixed with the central air airflow, then enters the outer secondary air expansion opening to be premixed with the inner direct-current air, and then is sprayed into the hearth together with the middle secondary air and the outer secondary air airflow.
Other components and connection relationships are the same as those in the sixth embodiment.
The specific implementation mode is eight: referring to fig. 6, the length L3 of the inner overgrate air flaring 10 and the length L2 of the middle overgrate air flaring 11 of the present embodiment are equal; the length L3 of the inner secondary air flaring 10 is 0.6-0.8 times of the length L1 of the outer secondary air flaring 12; the length L4 of the primary air flaring 9 is 0.5-0.7 times of the length L3 of the inner secondary air flaring 10.
According to the embodiment, the three premixing sections are added, so that the mixing of the primary air-powder mixture and the secondary air is further delayed, the rotational flow strength of the secondary air is enhanced, the staged combustion of pulverized coal is realized in a three-stage premixing mode, a stable central backflow area is formed in an outlet area of a combustor, the retention time of the primary air pulverized coal in the central backflow area is prolonged, the pulverized coal is stably combusted, the generation of nitrogen oxides is effectively inhibited, and the pulverized coal burner is suitable for subbituminous coal, lean coal and anthracite.
Other components and connection relationships are the same as those in the sixth embodiment.
The specific implementation method nine: the present embodiment is described with reference to fig. 7, and the multi-stage air distribution cyclone burner with radially outer dense and inner dilute air in the present embodiment includes a central tube 1, a primary air tube 2, an inner secondary air tube 3, an outer secondary air tube 5, an inner cyclone 13, an outer cyclone 14, a secondary air box 15, a spoiler 7, a pulverized coal concentrator 6, a flow equalizing ring 8, and a spacer 16;
the vortex generator comprises a central tube 1, a primary air tube 2, a spacing tube 16, an inner secondary air tube 3 and an outer secondary air tube 5 which are sequentially sleeved together from inside to outside, a primary air channel is formed between the central tube 1 and the primary air tube 2, the spacing tube 16, the inner secondary air tube 3 and the outer secondary air tube 5 are adjacent to each other, an inner secondary air channel and an outer secondary air channel are sequentially formed from inside to outside, two ends of the spacing tube 16 are fixedly connected with the primary air tube 2 through annular plates to form a closed space, outlet ends of the primary air tube 2, the inner secondary air tube 3 and the outer secondary air tube 5 are provided with primary air flaring openings 9, inner secondary air flaring openings 10 and outer secondary air flaring openings 12 in a one-to-one correspondence mode, a vortex generator 7 is arranged on the inner wall of the outlet end of the primary air tube 2, an inner vortex generator;
the pulverized coal concentrator 6 comprises a support plate 6-1 and N concentrating rings 6-2, wherein N is an integer of 2-5;
the diameters of the N concentration rings 6-2 are sequentially increased along the flowing direction of the primary air pulverized coal, the adjacent two concentration rings 6-2 are arranged at a certain distance, the N concentration rings 6-2 are fixedly connected together through a support plate 6-1, the support plate 6-1 is fixedly connected to the outer wall of the central tube 1, and the N concentration rings 6-2 are arranged at one side adjacent to the outlet of the central tube 1;
the flow equalizing ring 8 is arranged on the inner wall of the primary air pipe 2, and the flow equalizing ring 8 is arranged adjacent to one side of the concentration ring 6-2 with larger diameter.
Preferably, the outer cyclone 14 is installed in the secondary air bellow 15, and the horizontal section of the primary air duct 2 and the horizontal section of the outer secondary air duct 5 are respectively welded on the secondary air bellow 15.
Other compositions and connection relationships are the same as those of the second, third or fourth embodiment.
The detailed implementation mode is ten: referring to fig. 7, the thickness of the spacer 16 is 0.05 to 0.4 times the distance S1 between the outer wall of the center tube 1 and the inner wall of the primary air duct 2.
Other components and connections are the same as in the ninth embodiment.
The concrete implementation mode eleven: referring to fig. 7, the present embodiment will be described, in which the spread angle β of the primary air flare 9 is in the range of 10 ° to 20 °, the spread angle θ of the outer secondary air flare 12 is in the range of 20 ° to 25 °, and the spread angle θ of the inner secondary air flare 10 is in the range of 20 ° to 25 °.
Other components and connections are the same as in the ninth embodiment.
The specific implementation mode twelve: in the present embodiment, the end of the inner overfire air flare 10 and the end of the overfire air flare 9 are flush with each other, as described with reference to fig. 8.
Other components and connections are the same as in the ninth embodiment.
The specific implementation mode is thirteen: in the present embodiment, the length L4 of the primary air flared opening 9 and the length L3 of the inner secondary air flared opening 10 are equal to each other in the present embodiment described with reference to fig. 8; the length L4 of the primary air flaring 9 is 0.4-0.7 times of the length L1 of the outer secondary air flaring 12.
Other components and connections are the same as those in the twelfth embodiment.
The specific implementation mode is fourteen: referring to fig. 9, the length L3 of the inner overfire air flared end 10 is 0.6 to 0.8 times the length L1 of the outer overfire air flared end 12 in the present embodiment; the length L4 of the primary air flaring 9 is 0.5-0.7 times of the length L3 of the inner secondary air flaring 10.
Other compositions and connections are the same as for the nine, ten or eleven embodiments.
The two forms of burner of the present invention were applied to a boiler of the HG-1913/25.4-PM8 type: when the coal is used for combustion, the emission of the nitrogen oxide compounds is as follows:
1. when bituminous coal is burned, Vdaf is 26.35%, Aar is 22.65%, Mt is 10.23%, Qnet, ar is 21.18Mj/kg (wherein Vdaf is dry ash-free base volatile matter, Aar is received base ash parameter, Mt is total moisture parameter, Qnet and ar are received base low-grade calorific value), and the discharge amount of nitrogen oxides at the tail part of the boiler is 210mg/m after 24 combustors all adopt the novel combustor of the invention3The following.
2. When the mixed coal of 50 percent of lean coal and 50 percent of soft coal is combusted: wherein the lean coal is chemically analyzed as follows: vdaf-19.9%, Aar-32.65%, Mt-7.2%, Qnet, ar-19.13 Mj/kg, where the chemical analysis of bituminous coal is as follows: vdaf is 26.35%, Aar is 22.65%, Mt is 10.23%, Qnet, ar is 21.18Mj/kg, and the discharge amount of nitrogen oxides at the tail of the boiler after 24 burners adopt the novel burner is below 270mg/m 3.
The experimental data show that the invention can ensure that the nitrogen oxide reaches the standard when different coals are combusted, the discharge amount of the nitrogen oxide after combustion meets the relevant specified standard, and the invention can be suitable for the combustion of more coals.
The working principle of the first scheme of the invention is as follows: the primary air-powder mixture enters the primary air pipe 2 through the powder feeding pipeline, the primary air pipe of the burner is internally provided with the pulverized coal concentrator 6, the diameter of a concentration ring 6-2 of the pulverized coal concentrator 6 is sequentially increased along the flowing direction of primary air, the primary air-powder mixture is divided into two parts after passing through the pulverized coal concentrator 6, a concentrated pulverized coal region is formed near the inner wall region of the primary air pipe 2, a light pulverized coal region is formed near the outer surface region of the central air pipe 1, meanwhile, due to the existence of the flow equalizing ring 8, the air speed of the inner wall region of the primary air pipe 2 is reduced, the scouring of the primary air-powder mixture on the primary air pipe 2 is effectively reduced, the service life of the device is prolonged, and meanwhile, due to the existence of the flow equalizing ring and the vortex generator 7, the primary air-powder is. The invention realizes the staged combustion of pulverized coal fuel in the radial direction and the circumferential direction, increases the fuel quantity of a central backflow area, reduces the generation of nitrogen oxides, improves the stable combustion capability of the combustor, simultaneously forms a small vortex ring around a vortex generator, attaches the vortex ring to the root of a high-temperature backflow area, and in the small vortex area, the pulverized coal is easy to catch fire to strengthen the ignition characteristic of the pulverized coal, thereby ensuring the stable combustion characteristic of the invention. The secondary air respectively enters the inner secondary air pipe 3, the middle secondary air pipe 4 and the outer secondary air pipe 5 through the secondary air bellows 15, the middle secondary air is one straight-flow air, the air quantity is small, the air speed is low, the penetrating capacity and the primary air entrainment capacity are weak, the primary air cannot be excessively entrained, the distance between the primary air and the peripheral main secondary air is increased, the mixing of the primary air and the secondary air is delayed, the inner swirler 13 is arranged in the middle secondary air pipe 4, the outer swirler 14 is arranged in the outer secondary air pipe 5, the middle secondary air and the outer secondary air rotate, the rotation directions of the middle secondary air and the outer secondary air are consistent, the middle secondary air and the outer secondary air are sprayed into a hearth through the middle secondary air nozzle and the outer secondary air nozzle, a proper central backflow area is formed in a burner area.
The working principle of the second scheme of the invention is as follows: the primary air-powder mixture enters the primary air pipe 2 through the powder feeding pipe, the coal powder concentrator 6 is arranged in the primary air pipe 2, the diameter of a concentrating ring 6-2 of the coal powder concentrator 6 is sequentially increased along the flowing direction of the primary air-powder coal, the primary air-powder coal mixture is divided into two parts after passing through the coal powder concentrator 6, a coal powder area is formed in an area close to the inner wall of the primary air pipe 2, a light coal powder area is formed in an area close to the outer surface of the central pipe 1, and the primary air-powder coal powder is distributed at intervals in a strand of thick coal and light coal in the circumferential direction at the outlet end of the primary air pipe 2 under the action of the spoiler 7, so that the staged combustion of coal powder fuel in the radial direction and the circumferential direction is realized. Meanwhile, a small vortex ring is formed around the spoiler 7 and attached to the root of the high-temperature backflow area, and in the small vortex area, pulverized coal is easy to catch fire to strengthen the ignition characteristic of the pulverized coal, so that the stable combustion characteristic of the invention is ensured. The secondary air respectively enters the inner secondary air pipe 3 and the outer secondary air pipe 5 through the secondary air bellows 15, and a spacing cylinder 16 is arranged between the primary air pipe 2 and the inner secondary air pipe 3, so that primary air pulverized coal mixture and secondary air at the outlet end of the device are sprayed at intervals, the distance between the primary air and peripheral main stream secondary air is increased, the mixing of the primary air and the secondary air is delayed, the inner cyclone 13 is arranged in the inner secondary air channel, the outer cyclone 14 is arranged in the outer secondary air channel, so that the inner secondary air and the outer secondary air rotate, the rotating directions of the inner secondary air and the outer secondary air are consistent, and the inner secondary air and the outer secondary air are sprayed into a hearth through the inner secondary air nozzles, and a proper central reflux area is formed in the device, so that the pulverized coal is stably.
Claims (10)
1. The utility model provides a radial outer dense interior thin cyclone burner of multistage distribution of wind which characterized in that: the device comprises a central pipe (1), a primary air pipe (2), an inner secondary air pipe (3), a middle secondary air pipe (4), an outer secondary air pipe (5), an inner cyclone (13), an outer cyclone (14), a secondary air bellow (15), a spoiler (7), a pulverized coal concentrator (6) and a flow-equalizing ring (8);
the central tube (1), the primary air tube (2), the inner secondary air tube (3), the middle secondary air tube (4) and the outer secondary air tube (5) are sequentially sleeved together from inside to outside, and a primary air channel, an inner secondary air channel, a middle secondary air channel and an outer secondary air channel are sequentially formed between the adjacent primary air tube and the inner secondary air tube from inside to outside, the outlet ends of the primary air tube (2), the inner secondary air tube (3), the middle secondary air tube (4) and the outer secondary air tube (5) are correspondingly provided with a primary air flaring (9), an inner secondary air flaring (10), a middle secondary air flaring (11) and an outer secondary air flaring (12) one by one, the spoiler (7) is arranged on the inner wall of the outlet end of the primary air tube (2), the inner swirler (13) is arranged in the middle secondary air channel, and the outer swirler (14) is arranged in;
the pulverized coal concentrator (6) comprises a support plate (6-1) and N concentrating rings (6-2), wherein N is an integer of 2-5;
the diameters of the N concentration rings (6-2) are sequentially increased along the flowing direction of primary air pulverized coal, a certain distance is reserved between every two adjacent concentration rings (6-2), the N concentration rings (6-2) are fixedly connected together through a support plate (6-1), the support plate (6-1) is fixedly connected to the outer wall of the central pipe (1), and the N concentration rings (6-2) are arranged on one side, close to the outlet of the central pipe (1);
the flow-equalizing ring (8) is arranged on the inner wall of the primary air pipe (2), and the flow-equalizing ring (8) is arranged near one side of the concentration ring (6-2) with larger diameter.
2. The multi-stage air-distribution radially outer rich and inner lean cyclone burner as claimed in claim 1, wherein:
the N concentration rings (6-2) are all conical rings, the conicity of the N concentration rings (6-2) is equal, and the included angle delta between the generatrix of each concentration ring (6-2) and the central line of the central pipe (1) is 20-40 degrees.
3. The multi-stage air-distribution radially outer rich and inner lean cyclone burner as claimed in claim 1, wherein: the flow-equalizing ring (8) is arranged on the inner pipe wall of the primary air pipe (2) between the primary air flaring (9) and the pulverized coal concentrator (6), the distance Ls from the end part of the flow-equalizing ring (8) close to the primary air flaring (9) to the end part of the primary air flaring (9) is 4-8 times of the distance S1 from the outer wall of the central pipe (1) to the inner wall of the primary air pipe (2), and the thickness Hs of the flow-equalizing ring (8) is 0.04-0.1 times of the distance S1 from the outer wall of the central pipe (1) to the inner wall of the primary air pipe (2).
4. The multi-stage air-distribution radially outer rich and inner lean cyclone burner as claimed in claim 1, wherein: the spoiler (7) is composed of M trapezoidal plates with plate surfaces on the same plane, M is an integer of 8-16, the M trapezoidal plates are uniformly arranged at the outlet end of the inner wall of the primary air pipe (2), two adjacent trapezoidal plates are arranged at a certain gap, and the height S of each trapezoidal plate is 0.1-0.4 times of the distance S1 from the outer wall of the central pipe (1) to the inner wall of the primary air pipe (2).
5. The multi-stage air-distribution radially outer rich and inner lean cyclone burner as claimed in claim 1, wherein: the range of the expansion angle beta of the primary air flaring (9) is 15-25 degrees, the range of the expansion angle gamma of the middle secondary air flaring (11) is 20-25 degrees, the range of the expansion angle theta of the outer secondary air flaring (12) is 20-25 degrees, and the range of the expansion angle upsilon of the inner secondary air flaring (10) is 20-25 degrees.
6. The multi-stage air-distribution radially outer rich and inner lean cyclone burner as claimed in claim 1, wherein: the end part of the inner secondary air flaring (10), the end part of the middle secondary air flaring (11) and the end part of the primary air flaring (9) are arranged in parallel.
7. The multi-stage air-distribution radially outer rich and inner lean cyclone burner as claimed in claim 6, wherein: the length L4 of the primary air flaring (9), the length L3 of the inner secondary air flaring (10) and the length L2 of the middle secondary air flaring (11) are all equal; the length L4 of the primary air flaring (9) is 0.4-0.7 times of the length L1 of the outer secondary air flaring (12).
8. A multi-stage air distribution radially outer rich and inner lean cyclone burner as claimed in any one of claims 1 to 5, wherein: the length L3 of the inner overgrate air flaring (10) is equal to the length L2 of the middle overgrate air flaring (11); the length L3 of the inner secondary air flaring (10) is 0.6-0.8 times of the length L1 of the outer secondary air flaring (12); the length L4 of the primary air flaring (9) is 0.5-0.7 times of the length L3 of the inner secondary air flaring (10).
9. The utility model provides a radial outer dense interior thin cyclone burner of multistage distribution of wind which characterized in that: the device comprises a central pipe (1), a primary air pipe (2), an inner secondary air pipe (3), an outer secondary air pipe (5), an inner cyclone (13), an outer cyclone (14), a secondary air box (15), a spoiler (7), a pulverized coal concentrator (6), a flow-equalizing ring (8) and a spacing cylinder (16);
the central tube (1), the primary air pipe (2), the spacing tube (16), the inner secondary air pipe (3) and the outer secondary air pipe (5) are sequentially sleeved together from inside to outside, a primary air channel is formed between the central tube (1) and the primary air pipe (2), the spacing tube (16), the inner secondary air pipe (3) and the outer secondary air pipe (5) are adjacent to each other and sequentially form the inner secondary air channel and the outer secondary air channel from inside to outside, two ends of the spacing tube (16) are fixedly connected with the primary air pipe (2) through annular plates respectively to form a closed space, the outlet ends of the primary air pipe (2), the inner secondary air pipe (3) and the outer secondary air pipe (5) are provided with primary air flaring holes (9), inner secondary air flaring holes (10) and outer secondary air flaring holes (12) in a one-to-one correspondence manner, the vortex generator (7) is arranged on the inner wall of the outlet end of the primary air pipe (2), the outer swirler (14) is arranged in the outer secondary air channel;
the pulverized coal concentrator (6) comprises a support plate (6-1) and N concentrating rings (6-2), wherein N is an integer of 2-5;
the diameters of the N concentration rings (6-2) are sequentially increased along the flowing direction of primary air pulverized coal, a certain distance is reserved between every two adjacent concentration rings (6-2), the N concentration rings (6-2) are fixedly connected together through a support plate (6-1), the support plate (6-1) is fixedly connected to the outer wall of the central pipe (1), and the N concentration rings (6-2) are arranged on one side, close to the outlet of the central pipe (1);
the flow-equalizing ring (8) is arranged on the inner wall of the primary air pipe (2), and the flow-equalizing ring (8) is arranged near one side of the concentration ring (6-2) with larger diameter.
10. The multi-stage air-distribution radially outer rich and inner lean cyclone burner of claim 9, wherein: the N concentration rings (6-2) are all conical rings, the conicity of the N concentration rings (6-2) is equal, and the included angle delta between the generatrix of each concentration ring (6-2) and the central line of the central pipe (1) is 20-40 degrees.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920510791.0U CN209840083U (en) | 2019-04-15 | 2019-04-15 | Multistage air distribution radial outer thick inner thin cyclone burner |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201920510791.0U CN209840083U (en) | 2019-04-15 | 2019-04-15 | Multistage air distribution radial outer thick inner thin cyclone burner |
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| CN209840083U true CN209840083U (en) | 2019-12-24 |
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| CN201920510791.0U Withdrawn - After Issue CN209840083U (en) | 2019-04-15 | 2019-04-15 | Multistage air distribution radial outer thick inner thin cyclone burner |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109931605A (en) * | 2019-04-15 | 2019-06-25 | 北京国电龙高科环境工程技术有限公司 | A kind of outside dense interior light turbulent burner of diameter of multistage air distribution |
| CN111594830A (en) * | 2020-05-20 | 2020-08-28 | 哈尔滨工业大学 | High-efficiency low-NOx double-vortex flow pulverized coal burner |
-
2019
- 2019-04-15 CN CN201920510791.0U patent/CN209840083U/en not_active Withdrawn - After Issue
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109931605A (en) * | 2019-04-15 | 2019-06-25 | 北京国电龙高科环境工程技术有限公司 | A kind of outside dense interior light turbulent burner of diameter of multistage air distribution |
| CN109931605B (en) * | 2019-04-15 | 2024-05-28 | 北京国电龙高科环境工程技术有限公司 | Multistage air distribution radial outer thick and inner thin cyclone burner |
| CN111594830A (en) * | 2020-05-20 | 2020-08-28 | 哈尔滨工业大学 | High-efficiency low-NOx double-vortex flow pulverized coal burner |
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